In recent years, displays mounted on television sets, personal computers, information terminal assistants, and so forth have been increasingly required to have higher performance. There have been advances in the research and development of various types of display devices, such as cathode ray tube displays, liquid crystals, plasma displays (PDPs), and organic EL displays. In particular, liquid crystal displays are thin and light in weight and thus compose the major portion of a current display market. However, liquid crystal displays have narrow viewing angles and low image recognition performance when viewed from an oblique direction, compared with conventional cathode ray tube displays.
As a method for improving viewing angle characteristics of a liquid crystal display device, a method is disclosed in which phosphors and scattering members are arranged on the front of a liquid crystal display device, a part of blue light from a polarized collimated light source is used for blue display, and a part of the blue light is color-converted into red and green with the phosphors, thereby performing display (for example, see PTLs 1 and 2).
Organic EL displays are display devices having excellent display characteristics, such as high contrast, wide viewing angles, and high-speed response. To achieve full-color display, RGB light-emitting layers are required to be patterned by mask deposition, thus causing difficulty in increasing the definition and the size.
Meanwhile, a method for emitting light from RGB phosphors using a monochromatic organic EL as an excitation light source is disclosed (for example, see PTL 3).
In a phosphor color conversion display, in the case where a black matrix is disposed, light emitted from phosphors is absorbed or confined in the matrix, so that the light-output efficiency is not increased.
In contrast, a method is reported in which a white paste is used for a partition of a PDP (for example, see PTL 4).
Regarding other conventional techniques, in a phosphor color conversion display including an organic EL element serving as an excitation light source, a structure is reported in which a reflective film is disposed on a side face of a phosphor layer (for example, see PTL 5).